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Old Oct 13, 2003, 9:52 AM   #11
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For the exposure all that is important are the ends of the histogram. The interior parts help you associate image components with the scene, but the ends represent the limit of the exposure. If there is a pure white roof in a scene you expect the histogram to be smushed against the right edge. In a case like that determine the exposure with the spot meter on the most important or more critical part of the image and apply the histogram to that if you can. The more critical areas are ones with highlights. A prosumer digital camera doesn’t have a lot of exposure latitude and it is easy to blow the highlights. Blown highlights are just gone but it is usually possible to pull out shadow detail in post processing, so people tend to reduce the exposure to be conservative.

If you modify the auto-exposure the modification is in the opposite direction from what some people expect. If there is a large white object in the frame you have to increase the exposure and if there is a large black area you have to decrease it. Frame the camera completely within a pure white piece of paper and the auto exposure will make it gray. You obviously have to increase the exposure of a white sheet of paper to make it come out white. The opposite would be true of a black matte piece of paper. The camera would try to make it gray and you would have to decrease the exposure. If you shoot in snow or on the beach you usually have to increase the EV in auto. You can often just use the spot meter.

If you have a pure white item in the photo and the histogram doesn’t show it piled up on the right you know the camera treated it as a face and underexposed. You always have to relate the histogram to the scene or the histogram by itself is useless. I keep mine always visible in the EVF and try to take the time to relate it to the scene on every shot.

The histogram mode on my scanner has the feature of showing areas on the preview that have blown highlights or shadow detail due to the settings. I wish my camera had it like the Nikons – sounds like a nice feature as it is great on the scanner. And it think eliminating some of the interior of the histogram would give you a better scale on the ends, which are the only thing you can affect. The histogram has to be small in the viewfinder and a better scale would be helpful. A regular real time histogram is useful without either of those, but they would be an improvement.
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Old Oct 13, 2003, 11:56 AM   #12
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I got introduced to Histograms when I was tinkering with Photoshop long before I had this Olympus C-740 on my hands. :lol:

If you have any other access to a similar program like Photoshop, like say, Paintshop Pro, I think you can play around with the histograms there, that way you'll have a much better grasp on the concept.
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Old Oct 14, 2003, 9:33 PM   #13
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THX again everyone - this has been very helpful. Best - john
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Old Oct 14, 2003, 9:34 PM   #14
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THX again everyone - this has been very helpful. Best - john
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